Configuration

The Kate configuration menu is user-friendly, and should mostly be
intuitive. One useful editor config option is the persistent selection
setting. If persistent selection is switched on, the selection made will
remain even when you move the cursor away and/or type: so you can leave
something selected while you're typing elsewhere in the document.

The shortcuts menu allows you to set your own keyboard shortcuts for
various functions, which is great if you're used to a particular key
combination for doing a particular thing, or if you have a non-standard
keyboard.

Kate's plugin capability can also be accessed from the config menu. You can
turn on the plugins that are installed by default here; or you can find or
write your own plugins and install them. The default plugins include
incremental (as-you-type) search, and a plugin which allows you to use the
kdata thesaurus and spellcheck functions, if they're installed on your system
(you'll need ispell or aspell, at least). There's also a
word completion plugin, which gives popup word completion. Note that it
doesn't complete from a dictionary; it completes from words you've previously
typed in the document.

Configuring with document variables

The other way to set configuration options in advance is by using document
variables. This involves putting a configuration line (which can be in a
comment) in a particular document. So for example, in a C++ script, you might
want to set tabs to be interpreted as spaces (to agree with a particular
coding style), and C-style indentation (see the next article in this series
for more on automatic indentation). In which case, you would put this line in
either the first or the last 10 lines of your file:

// kate: set-replace-tabs on; indent cstyle;

(The // is just the C++ comment marker: the important part from the
point of view of Kate is that the line should start with kate:.)
The syntax of the document variable line is the same as the syntax used to
set options on the command-line (see below).

Document variables have the highest priority when config options are being
applied, so they're useful if you want a particular document to be treated
differently from your normal setup. The set of variables that can be set in
this way is fairly comprehensive, including various colour settings and syntax
highlighting as well as selection options, display options, indent, folding,
and other options.

You can also set per-filetype (as opposed to per-file) options via the
configuration screen, under the Filetypes tab.